I found a very simple tip for improving(at least in my case) consistency. I found that just grabbing a glass of water for a match has done me wonders. While the other player is playing I can just take a few sips of water to help keep my cool. It also takes my mind away from what the other person is doing. Then once they have missed, chalked up after their shot, cussed, threw their cue, and finally sat down I can take another final drink and step to the table with no thought of all the other stuff that is going on except for what I have to do at the table.